Low Temperature Elastic Properties of CuZrTi Bulk Metallic Glass

Abstract

Temperature dependent elastic constants C_ij(T) of Cu₆₀Zr₃₀Ti₁₀ bulk metallic glass (BMG) have been studied using MHz frequency range electromagnetic acoustic resonance (EMAR) from 4.5 to 300 K. At ambient temperature, the BMG shows low shear/bulk modulus ratio (or equivalently high Poisson ratio) compared with that of corresponding crystalline state dues to the dense random packed glassy structure. Analysis of C_ij(T) based on the Einstein type lattice vibration model revealed the notable softening in transverse mode acoustic phonons. This unusual vibrational property suggests the existence of liquid like weakly bonded region in the BMG.